Vertical‐Aligned Li₂S–Graphene Encapsulated within a Carbon Shell as a Free‐Standing Cathode for Lithium–Sulfur Batteries

Abstract

Construction of a novel matrix with both high conductivity and an excellent confinement effect for polysulfides is of great importance for developing high-performance lithium-sulfur (Li-S) batteries. In this work, we have developed a double-modification strategy to integrate lithium sulfide (Li S) into a conductive composite network consisting of vertical graphene (VG) arrays and an amorphous carbon shell, forming an integrated cathode (VG/Li S-C). Facile liquid-solution/evaporation methods in combination with chemical vapor deposition were successfully adopted for preparation of the above cathode. Due to the enhanced electrical conductivity and noticeable blocking effect for the shuttle of polysulfides, the binder-free flexible VG/Li S-C cathode exhibits high rate performance and reinforced cycles (656.2 mAh g after 100 cycles). The pronounced electrochemical performance is ascribed to the unique architecture with a coherent conductive network of VG and the carbon shell, which not only provides a conductive network for fast reaction kinetics, but also forms a durable protective shield to suppress the shuttle of polysulfides. Our research further demonstrates the synergistic effectiveness by means of inner and outer carbon matrixes for electrochemical enhancement of Li-S batteries.

Multiscale Graphene‐Based Materials for Applications in Sodium Ion Batteries

“…Sometimes, employing second components might lead to the destruction of the pristine graphene conductive networks and mechanical flexibility . Some researchers proposed that the addition of a third phase such as carbon layer is able to solve this problem . For instance, Gao et al prepared a series of 3D integrated carbon/red phosphorus/graphene aerogel composites (C@P/GA) with different P content via a vapor‐redistribution strategy ( Figure 8 a,b,g) .…”

Confining Sulfur in Integrated Composite Scaffold with Highly Porous Carbon Fibers/Vanadium Nitride Arrays for High‐Performance Lithium–Sulfur Batteries

“…Lithium–sulfur batteries (LSBs) emerge and have been pursued as an alternative to LIBs due to their ultrahigh theoretical energy density of 2600 Wh kg −1 about seven times larger than LIBs . Although elemental sulfur electrode has a variety of advantages such as high capacity, easy processing, low cost, and nontoxicity, the sufficient utilization of sulfur cathode is severely hindered by its insulating nature, volume fluctuation during cycling, as well as the adverse “shuttle effect” caused by the dissolution and diffusion of reaction intermediate polysulfides . In such a context, appropriate steps must be taken to overcome these headwinds.…”

Recent Developments of All‐Solid‐State Lithium Secondary Batteries with Sulfide Inorganic Electrolytes

“…Lithium‐sulfur batteries (LSBs) with a high theoretical energy density (2600 Wh Kg −1 ) are regarded as one of the most promising candidates to meet the growing application demands . However, despite great progress, their extensive application is still restrained by the shuttle effect of soluble polysulfide intermediates.…”